When buying my first bag of chalk, I fell for it. The money = quality scam. I didn’t get Friction Labs–that’d be too mainstream, but I did get some Primo Chalk. It’s nothing special. It is super soft though which I do like. Anyways, Primo Chalk purports itself as antibacterial and soothing for the skin. They say it does it because they added essential oils to the chalk. So I did some research.
Basically only eucalyptus (essential) oil has been shown to have significant antibacterial properties at levels that are safe for human consumption/skin contact. (Some basic research here)
So I bought some eucalyptus oil, and some peppermint, and some tangerine. I dumped a bunch of droplets in my bag of Primo chalk.
I doubt bacteria can grow in chalk anyways–way too dry an environment, but at least my chalk smells good.